The present disclosure relates to a communication apparatus and a communication system which perform facsimile communication by way of an IP (Internet Protocol) network and, in particular, to a technology of sending image data via facsimile communication.
Conventionally, there are known communication apparatuses such as G3 (Group 3) facsimile apparatus which performs facsimile communication in accordance with a communication procedure based on the ITU-T Recommendation T.30 by way of a telephone network, communication apparatus which sends and receives an email in accordance with a communication procedure based on the ITU-T Recommendation T.37 by way of an IP network, and network facsimile apparatus which performs facsimile communication in accordance with a communication procedure based on the ITU-T Recommendation T.38 by way of an IP network.
Specifically, a network facsimile apparatus is known which has an email processing function of sending and receiving image data via email by way of a local area network, and a sending function of sending image data in accordance with the G3 facsimile transmission procedure by way of an analog public network. It is also known that a sending apparatus which has sent image data via email sends email requesting cancelation of the previous image data sending, and the receiving apparatus deletes the image data which is being requested for cancelation if it remains in a mailbox.
A G3 facsimile apparatus makes a call by way of a telephone network, and confirm normal communication to be possible after receiving a response from the receiving facsimile apparatus, and then starts sending of image data.